(a) Field of the Invention
The present invention relates to a thin film transistor (TFT) array panel for a liquid crystal display (LCD) and a method for manufacturing the same using four photolithography steps.
(b) Description of the Related Art
An LCD is one of the most widely used flat panel displays (FPDs). The LCD includes two panels having two kinds of electrodes for generating electric fields and a liquid crystal layer interposed between the two panels. The transmittance of incident light is controlled by the intensity of the electric field applied to the liquid crystal layer.
The field-generating electrodes are provided at both or one of the panels. One of the panels has at least one of the two types of electrodes includes switching elements such as thin film transistors.
In general, a TFT (thin film transistor) array panel of an LCD includes a plurality of pixel electrodes, and TFTs controlling signals supplied to the pixel electrodes. The TFT array panel is manufactured using a photolithography process using a plurality of photomasks. Five or six photolithography steps are used in producing a TFT array panel. Since the photolithography process is expensive and takes long, it is desirable to reduce the number of the photolithography steps. Even though manufacturing methods using only four photolithography steps have been suggested, these proposed methods are not easy to implement.